Biological significance of expression of nitric oxide synthases in neurogenic bladder / 中华泌尿外科杂志

ABSTRACT

Objective To explore the expression of nitric oxide synthases including neuronal nitric oxide synthases(nNOS), inducible nitric oxide synthases(iNOS), endothelial nitric oxide synthases (eNOS) in neurogenic bladder tissues, and analyze it's producing feature and significance. Methods There were 30 cases with neurogenic bladder(18 males, 12 females). The average age was 6.3±3.1 years. All patients appeared with myelodysplasia, urinary and fecal incontinence in different degree. Twenty-six cases were manifested with hyperreflexia bladders, and all patients were treated with surgical procedures. During operation, collected bladder tissue samples including tissues of apex vesicae and tissues of bladder neck, and all tissues were enveloped with mineral wax. All tissues were detected for nNOS, iNOS, and eNOS respectively in tissues of apex vesicae and tissues of bladder neck,and with normal bladder tissues as control group (bladder tissues of hypospadia, 10 cases), and according to clinical features, to explore the expression of NOS, and to analyze the relationship among them. Results In normal apex vesicae tissues, all cases stained with nNOS, and distributed among bundles of smooth muscles, and surface of smooth muscles and interstitial tissue, histochemica;score (HS) 2.8-4.0 and 1.2-2.7. There were no stained cells in bladder tissues of iNOS, and HS was very low, HS0-0. 4 and 0-0.1 ;eNOS mainly distributed in interstitial tissues in rarefaction manners, and mainly in vascular endothelial cell (VEC), and smooth muscles had no stainings the most expression among them was nNOS, and mainly distributed in bladder neck tissues. In neurogenic bladder tissues, the main expression of NOS type was iNOS, and nNOS decreased significantly. eNOS mainly expressed in VEC among interstitial tissues, and had no staining in smooth muscle cells and collagenoblast and rarefaction of microvessel in bladder tissues, and microvessel density decreased significantly than normal bladder tissues. Microvessal density(MVD) in bladder tisssus (6. 8± 3.2/100per square) was less than that in normal tissues (16.7±6.3/100 per square). Conclusions In normal bladder tissues, nNOS mainly distributes in bladder neck and urethra, and nitric oxide mainly derives from nNOS. Much more matrix fibers, fewer nitrogenergic nerves, and less nNOS expression are seen in neurogenic bladder interstitial tissue. There are more iNOS expressions in bladder tissues,and NO is mainly derived from iNOS, and it may play an important role in pathological bladder tissues, especially in fibrosis of bladder wall. eNOS may be considered as angiopoietic labeling, and may evaluate the blood supply of bladder.